Conventionally, there has been proposed a technology for recognizing a person from a face region of the person included in moving image data captured by a monitor camera or the like based on previously stored feature information of a face image. In this case, feature information is extracted from the face region included in the moving image data. Then, if a condition in which a measure indicating similarity (the degree of similarity) between the extracted feature information and the previously stored feature information is greater than or equal to a predetermined threshold value is met, the person is recognized as a preregistered person.
The illumination environment varies and the photographing state of the face of a person changes, depending on the installation place of a monitor camera or the like. Accordingly, it is necessary to set a threshold value to recognize a person as a preregistered person based on the measure indicating similarity, whenever necessary, for each installation location such that a false rejection rate (FRR) and a false acceptance rate (FAR) are within an allowable range in terms of operation. However, in the above-mentioned known technology, it is difficult to accomplish easy setting of the threshold value.